A water distribution system typically includes water mains for delivering water through the system with valves located in the water mains to control the flow of water through the mains. A water distribution system may be laid out in a municipality or other geographic area with the valves strategically placed to control selectively the flow of water to various parts of the system.
The water mains and the associated valves of a water distribution system typically are located underground. Each of the underground valves is subject to corrosion, build-up of dirt and other debris with the passage of time. These build-ups and corrosion deposits can restrict water flow through the valve and greatly increase the torque required to open or close that valve. The aging of a valve may cause the packing around a valve stem to leak. Furthermore, a valve may be damaged by workmen who turn the valve for a variety of reasons such as a requirement to redirect water service or by an unauthorized person who attempts to turn the valve.
An inspection of all of the valves in a water distribution system is necessary for proper maintenance of the system. The inspection not only includes observing the condition of each valve, but also turning the valve stem of each valve to a fully closed position and a fully open position of the valve. Notation of the facility with which a given valve stem turns, number of stem revolutions to open and close the valve and the time required to make each turn forms a basis for proper evaluation of the condition of each valve. All system valves are assigned into inspection routes. Many routes may be required to make an inspection of all of the valves. A well-organized inspection route provides optimum utilization of time and manpower in inspecting selected valves of the system. Once the valves are inspected, information regarding each of the valves must be evaluated with a view to selecting valves which are in the greatest need of repair and to schedule repair of those valves before repairing valves having a lesser need.
A commonly used procedure for identifying the condition of valves in a system is to dispatch an inspection team to each of several routes so that at least one inspection team visits each valve location. The team inspects each valve and makes a written notation of the condition of the valve. Depending upon valve size, one or more members of the team turns the valve stem a number of turns to close the valve fully and to open the valve fully. The position of the valve after inspection, that is, whether it is left opened or closed, is recorded. In some instances, the inspection team is unable to turn a valve stem, especially the stem of a large valve that has been not turned for some time and corrosion of parts of the valve prevents free turning of a valve stem. In those cases where the inspection team is unable to turn the valve within the time allotted for inspecting the valve, the team notes the inability to turn the valve and moves onto the next valve location leaving the seized valve to be repaired by a maintenance crew. The exact count of the number of turns to open or close any valve is often lost in the course of making the turns. Thus, the recorded number of turns made by the valve stem to open or close the valve is not always accurate.
The recorded information gathered during inspection of each valve is deposited in a central location where it is available for analysis. Persons who are charged with the responsibility of supervising the maintenance of the system often find it difficult to grade accurately the condition of all of the valves in the system in order to prioritize maintenance of the valves. Difficulties arise because the information for each valve is either incomplete or not correct. The prioritization of repairs must be balanced both by condition of the valves and the relative distance between the valves in the system to effect efficient maintenance of the system valves.
It is desirable to provide a method and apparatus for identifying and recording the condition of each of the valves in the water distribution system. This method and apparatus would effect an efficient maintenance program for the valves by providing an apparatus to record accurately information relating to each valve inspected. Additionally, it would use computers for storing and sorting information regarding the condition and location of each valve in the system to make repairs in an efficient orderly manner.